The lockup solenoid on a 1999 Dodge Dakota's transmission isn't a single, easily accessible component like a starter solenoid. It's
inside the transmission itself, as part of the valve body. There's no external access to it; you'll need to remove the transmission to service or replace it.
Therefore, there's no "location" you can point to externally on the truck. To reach it, a transmission overhaul or at least a valve body rebuild would be required.
